This disclosure generally relates to systems and methods for braking a wheel of a vehicle. More specifically, this disclosure relates to systems and methods for braking a wheel of an aircraft.
A vehicle braking system typically combines both a braking control function to apply brakes and a skid reduction system, herein referred to as an “anti-skid system”. The braking control function includes the operator (hereafter referred to as the “pilot”) input, along with inputs from an automatic wheel-based brake control system, generically referred to as the “autobrake”. Many other braking control input functions can exist in both driven wheel systems such as automobiles and in non-driven wheel vehicles such as aircraft. These control inputs are characterized by smooth and uniform application and release. Noise on these inputs is detrimental to the long-term reliability of electric (electro-mechanical) and electro-hydraulic braking systems (the latter defined as a braking system where the clamping force in the brake is developed via hydraulic pressure, but the hydraulic pressure is generated by an electric motor, usually dedicated to the control function), due to excessive wear. An anti-skid system, on the other hand, is characterized by a rapid input to release a brake at the onset of a skid, and a continuing rapid response to control the deceleration of wheel speed in order to provide the optimal braking performance. Hence the anti-skid input to a braking control system is characterized by a rapid response. These two characteristics are in conflict.
The prior art design simply merges the brake pedal (and all other mode) commands in along with the anti-skid command, resulting in a braking signal input which needs to accomplish both goals. This design may result in excessive wear in the electric-mechanical or electro-hydraulic braking system.